How to Test a Perfume Properly: Why the First Minute Lies

A Saturday morning in a cold kitchen, the kettle just put on and the window still grey. One spray of Last Birthday Cake goes on the inside of the wrist, and up rise milk, wick, instant cocoa and bitter almond, a candle wick over a cup of cocoa. A sniff or two later it already reads fainter. Then someone comes down the stairs, leans in to say good morning and asks whose birthday it is.

The perfume is still there, and anyone who has not been breathing it smells it. Two things blur that first minute. The nose has already begun turning the volume down, and what it meets is mostly the top notes. Frédéric Malle gives those about 15 minutes, and after them comes the heart, in his view the perfume's real personality. One decant is enough to run a method that gets around both: a single perfume, worn on skin for a whole day and smelled with a rested nose.

The nose starts tuning out

For many smells, perception starts to fade after just one or two sniffs, says Pamela Dalton of the Monell Chemical Senses Center in Philadelphia. The fading is called olfactory adaptation, and it is specific. Repeated or prolonged exposure lowers your sensitivity to that particular smell, and the sensitivity returns with time once the exposure stops.

Some of it happens in the nose, where receptors that have just fired go quiet for a spell. Much of it happens further up, in the brain, and that share comes on faster.

Two weeks beside one smell

Dalton and Wysocki, at Monell in 1996, had people keep a single scent compound by their beds for two weeks. They came to need two, three and sometimes four times the original amount to detect it, and for most of them the dulled sensitivity was still there up to two weeks after the scent had been taken away.

One compound in a bedroom is a long way from a perfume on skin. It is still hard to read without thinking of a bottle worn every morning that seems to have gone quiet.

Dalton's advice for learning what your own home smells like is to go away for two weeks, or ask a friend over to sniff. She meant houses, but the logic carries to a wrist: the person on the stairs had not been breathing the perfume, so nothing had turned it down for them.

One perfume to a day

Adaptation also spills sideways. The same year, Monell researchers studied it as cross-adaptation: one smell dulling you to a different one. How much depends on how alike the two smells are, though not in any simple or predictable way. That is the case against the two-wrist test, where the second perfume is read by a nose the first may already have turned down. So it is one perfume a day, on skin, the same rule that runs through why two decants of the same perfume can smell different.

Fragrance sellers often offer coffee beans to clear the nose. Students at Beloit College, in a small study, sniffed coffee beans, lemon slices or plain air before picking one new fragrance out of four, and the coffee did no better than the lemon or the air. What the research does support is time away from the smell, since sensitivity comes back once the exposure stops.

Paper for names, skin for verdicts

Perfumers work from paper strips called mouillettes, and Galimard in Grasse passes on their trick of writing the scent's name on the strip first. A strip gives a fair first reading of how a perfume is built, but paper has none of the warmth or pH of skin.

On skin, a perfume comes apart ingredient by ingredient. Firmenich's researchers in Geneva showed it in 1995 with a collector fitted to the inner forearm: the ingredients rising off the skin each left at their own rate. The first minute belongs mostly to the part built to leave first.

Three perfumes the first minute gets wrong

The Romanian house Toskovat means its perfumes to be non-linear, like the memories behind them, and its manifesto adds a plea: "Please take your time understanding them!" Last Birthday Cake comes in three lines of notes, and the first is that cold kitchen: milk, wick, instant cocoa, bitter almond and malt. Then comes the cake itself, with Armagnac, stollen, brown sugar and vanilla custard. The last line turns dry and dark: styrax, tolu balsam, incense and papyrus, with a note named Chekhov's Gun waiting among them. A verdict taken in the first minute is a verdict on the first line alone, which is a strange way to judge a cake that ends in smoke.

The Jester opens on leather and tobacco, with raspberry, black pomegranate and spiced red wine bleeding through. Then it becomes a room of black tea, beeswax candles, velvet drapes and aged parchment, and it ends on sandalwood, saffron and burnt incense over ancient oak. In The Antagonist's story for it, the crowd cheers the mask and never sees the man, and the jester laughs because he sees everything. On a test day, the jester is whoever walked in after the spray.

Pornstar (Noyau Doux), from the same house as Last Birthday Cake, opens on ice, finger lime, chewing gum and dragon fruit, the first of its three note lines. Judge it there and you have judged the part built to leave first. A Pornstar Martini heart with amaryllis and Venus flytrap follows, and the last line is soft and skin-like: vanilla, meringue, persimmon and body lotion.

Running the day

Choose a day with no other perfume in it. In the morning, put a single spray on the clean inside of the wrist or forearm. Smell it once, properly, then leave it alone, because repeated and prolonged exposure is what dulls the nose to that one smell.

Malle, who tells people to wear the few they like best on the arm, puts his check at 20 minutes: do you still see yourself wearing it? Here the question goes to the day's one perfume.

Then live the day. Before each check, give the nose a while away from the perfume, with the wrist well away from your face. Midway through, ask someone who was not there for the spray what they smell. Later, when only the base remains, put Malle's other question to it: alone with the smell, away from the imagery and the packaging, do you still feel the same about it?

A decant is filled straight from the original bottle, never diluted or reformulated, so a test day on a decant is a test day on the perfume, and how many sprays a vial holds decides how many of those days there are. After the first day, undecided is a fair verdict.

In the story Toskovat wrote for Last Birthday Cake, the narrator is told again and again to make a wish. In the distance, a big boulder starts to roll on a hill. The narrator remains undecided.

Frequently asked questions

How do you test a perfume properly?

Wear one perfume a day, as a single spray on skin, and judge it across the whole day instead of the first minute. Check it after time away from the smell, ask someone who was not there when you sprayed it, and keep paper strips for a first reading only.

Why does a perfume seem to disappear soon after you put it on?

Partly olfactory adaptation and partly the top notes, which are very volatile, leaving first. For many smells, perception starts to fade after one or two sniffs, and the drop is specific to that smell, so someone who has not been near it still smells what has faded for you. Sensitivity comes back with time once the exposure stops.

Can you test two perfumes at once, one on each wrist?

It muddies the result. Smelling one scent can dull you to a different one, an effect called cross-adaptation that depends on how alike the two smells are in ways that are hard to predict, so test one perfume per day, on skin.

Do coffee beans reset your sense of smell?

In a small exploratory study at Beloit College in 2011, sniffing coffee beans did no better than sniffing lemon slices or plain air before picking out a new fragrance. What the research supports is time away from the smell, since sensitivity recovers once the exposure stops.